Control apparatus responsive to condition of rest or movement



y 2, 1961 R. w. LE GATES ETAL 2,982,902

CONTROL APPARATUS RESPONSIVE TO CONDITION OF REST OR MOVEMENT INVENTORS RALPH W.'.Le GATES MlCHAEL CSANADY an 8! r2 Z 2.

WITNESSE m T I i! 14 Patented May 2, 1961 CONTROL APPARATUS .RESPONSIVE T CONDI- TION OF REST OR MOVEMENT Ralph W. Le Gates, Glen Mills, and Michael Csanady,

Jr., Ridley Park, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania 1 Filed Jan. 8, '1960, Ser. No. 1,366

11 Claims. ('Cl. 318-481) This invention relates to a device for sensing the condition of rest or movement of a shaft movable angularly about its axis, and more particularly to a control device responsive to zero speed of a shaft for energizing a mecha msm.

As is well known in the turbine art, the shafts or rotors of elastic fluid turbines are turned slowly by a mechanism, after the turbine has been shut down, in order to assure uniform cooling of the rotor and also to facilitate starting of the turbine. It is the principal concern of the present invention to provide a rugged and dependable device which automatically engages and energizes the turning mechanism in response to the condition of rest of the rotor. Devices of this type may also be used to energize an electrical circuit connected to indicators, warning lights, instruments, and recorders, or any combination of them.

A device for carrying out the present invention comprises: first means providing at least two streams of energy vehicles, second means responsive to the receipt of energy from one or both streams, and a member which is movable incident to angular movement of the subject shaft about its axis. The movable member is provided with a series alternately comprising passageways and blocking elements for the streams. The series is movable across the paths of both streams and, furthermore, the series is arranged in such a manner that at least one stream of energy vehicles is permitted to flow to the energy responsive means when the shaft is stationary in any position. During angular movement of the shaft, on the other hand, the flow of energy vehicles toward the energy responsive means is interrupted.

In one embodiment. of the invention, the streams of energy vehicles are jets of fluid, such as oil. These jets are directed to respective inlets of a device which is responsive to fluid pressure. In this embodiment, a disc member driven by the shaft is provided with a series of jet passageways and blocking elements. The blocking elements deflect both jets away from the inlets when the shaft is moving angularly; but, when the shaft is stationary, there is always one jet passageway in registry with a fluid jet and an inlet regardless of the position of the movable member. In the latter case, fluid entering the inlet passes to the pressure responsive device and produces a response when a predetermined pressure is reached. During angular movement of the shaft, with this type of arrangement, the moving passageways each register momentarily with one jet and its associated inlet; but momentary registry provides insuflicient opportunity for the fluid jet to travel the length of the passageway before it is deflected away from the inlet. And, even 'if by chance some fluid particles should enter the inlet,

an intermittent or unsteady stream would not build up the pressure required to actuate the pressure responsive device.

The various objects, features and advantages of the invention will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a side view, partly in elevation and partly in vertical section of apparatus embodying the invention, shown together with schematically illustrated electrical circuitry;

Fig. 2 is a view taken along line IIII of Fig. 1;

Fig. 3 is a developed sectional 'view taken along line III-IlI of Fig. 2; and

Fig. 4 is a view similar to Fig. 3 but showing the invention in modified form.

Referring to the drawing in detail, in Fig. 1 the invention is shown applied to a turbine rotor 10. vIt is to be understood, however, that the invention may be applied to various other kinds of shafts angularly movable about their axes. The rotor 10 includes shafts 12 joined endto-end at their coupling flanges, and between which is secured a disc member 14.

The disc 14 is provided with a circular series of equally sized and equally spaced passageways 16. The latter extend axially and are arranged about the rotor axis and adjacent the periphery of the disc 14. Between each pair of passageways 16 is a part designated by the numeral 18 and termed blocking element, for reasons that will appear later. It will suffice to say, for the prment, that the passageways 16 permit the passage of streams of energy vehicles from one side of the disc 14 to the other, and the blocking elements 18 do not.

In the first embodiment, as best seen in Fig. 3, the streams of energy vehicles are ffuid jets, preferably oil jets, which issue from a pair of nozzles 20 receiving the pressurized fluid through a pair of conduits 22 leading froma pump 24. Although jets of oil serve as energycarrying vehicles in the present embodiment, it is obvious that other energy vehicles may be employed. The discharged fluid jets out of the nozzles 20 in the same general direction and in two generally parallel streams Whose paths are crossed by the series of passageways 16 and blocking elements 18. The relative attitudes and directions of flow of the jets are unimportant in the broad sense of the invention.

Aligned with and spaced from the nozzles 20, for receiving the fluid jets, are a pair of receiver holes or inlet openings 26. Each inlet opening 26 is connected to a tube 28 which leads to an accumulator 30 and energyresponsive means in the form of a pressure switch 32, the latter two parts being connected to their associated tube 28 in parallel. The accumulator 30 is a conventional storage vessel which accumulates fluid over a period of time, thereby providing a time delay before reaching a preset pressure which actuates the switch 32.

Preferably the accumulator 30 is above the level of its associated inlet opening 26 in order to provide it with good drainage to a sump 33. The size of the accumulator is a matter of choice, proportional in volumetric capacity to the desired time delay. In applications where a small time delay is desired the accumulator 30 may be eliminated, since the tube 28 serves, to some extent, as an accumulator.

Pressure switches are well-known devices, and many different types of them are commercially available. The kind used in the present arrangement, as shown in Fig. 1, comprises a flexible diaphragm 34 on which is carried a contact 36 movable with the diaphragm into engagement with a stationary contact 37 in response to fluid pressure of a predetermined level. As will be described later, the engagement of contacts 36 and 37 initiates the energization of a turning mechanism 40 which engages and then rotates the turbine rotor 10 at low speed, 3 rpm. for example. The turning mechanism 40 includes a motor 41 which drives the rotor through a worm 42 and a worm wheel 43.

The peripheral margin of the disc 14 moves in the space between the nozzles and the inletopenings 26 incident to rotation of the rotor 10, the series of passageways'16 and blocking elements 18 moving transversely across the paths of the fluid streams. The passageways are sized and spaced relative the fluid streams so they permit at least one fluid stream to flow therethrough when the rot'or10 is stationary in any position. It is essential to the first embodiment, therefore, for one passageway 16 always to be in registry with one stream and one inlet opening 26. It is also essential for the blocking elements 18 to be capable of deflecting both streams away from the inlet openings 26 during rotation of the rotor 10. To this 'end the stream from one nozzle 20 is positioned so that it just clears the leading edge 38 of one blocking element 18 at the same time that the other stream just clears the trailing edge 39 of the same or another blocking ele ment. Preferably, the transverse extent of each passageway 16, in the direction of movement of the series, is substantially equal to the aggregated extent of one blocking element 18 and both streams, and the transverse extent of each blocking element is substantially equal to the space between fluid streams. With this arrangement, it is therefore possible for one passageway 16 to be in registry with both fluid streams at the same time, and a stationary blocking element 18 can be disposed between a pair of fluid streams without deflecting either of them. Small manufacturing tolerances-are desirable in making this kind of device, if it is to be highly sensitive to a change in condition from movement or rest.

Nozzles 2 0 and inlet openings 26 may be enclosed in order to keep deflected fluid within a confined region. An enclosure is not shown, however, since it forms no part of the present invention. After having spent its energy, fluid is collected in the sump 33 and then drawn into the pump 24 through a suitable conduit 45 for recirculation. It is to be understood, however, that the invention is not limited to systems utilizing recirculated energy vehicles.

A second embodiment of the present invention is illustrated in Fig. 4, and there like reference numerals are employed to denote similar parts. The embodiment 'of Fig. 4 diflers from the first embodiment in that the pressure-responsive switch 32 is arranged to respond to back-pressure in the respective supply conduits 22 leading to the nozzles 20. Nevertheless, the same inventive concept is involved in arranging the positions of the passageways 16 and blocking elements 18 with respect to the streams so that at least one stream of energy vehicles flows to its associated switch 32 in any stationary position of the rotor 10.

In the embodiment of Fig. 4, a pair of nozzles 20 each receive pressurized fluid, preferably oil, through respective conduits 22 connected to a pump 24. Connccted to each of the conduits 22 is a branch tube 46, further connected in parallel to an accumulator 30 and a pressure responsive switch 32. To produce back-pressure in one or both of the branch tubes 46, at least one of the nozzles 20 is closed by a blocking element 18 when the disc member 14 is stationary in any position. A wipe or sliding fit between the outlet of the nozzle 20 and the locking elements 18 is preferable; in which case there is a slight clearance between these parts. Also, the blocking elements 18 of the second embodiment must extend transversely the same extent as the passageways 16 of the first embodiment. And, the passageways 16 of the second embodiment must extend transversely to the same extent as the blocking elements 18 of the first embodiment. Of course, this difference between embodiments in transverse extent of their passageways '16 and blocking elements 18 is required because in the embodiment of Fig. 4 it is necessary to block a. stream of energy vehicles to actuate switch 32, while unblocking a nozzle 20 produces the same response inthe other embodiment.

When the disc 14 of the second embodiment is at rest, at least one of the nozzles 20 is blocked by a blocking element 18; and this causes fluid pressure to build up in the conduit22, the associated bleed line 46, and the accumulator 30. After reaching a predetermined pressure in the switch 32 its contacts close to initiate energization of the turning mechanism 40.

The electrical circuitry and apparatus preferred 'for use in connection with both of the above-described embodiments will now be described as applied to the first embodiment. Generally stated, it is their function to supply electrical power to the motor 41 of turning mechanism 40 once the switch 32 is closed; and, furthermore, to continue supplying electrical power to the motor 41, even after switch 32 opens incident to rotation of the rotor 10 at low speed.

The electrical circuitry includes an actuating relay 50 including an operating-coil 52, a primary switch'54 which is closed during periods when the coil 52 is energized, and a hold switch 56 for establishing a holding circuit through the relay coil 52. The operating coil 52 is connected through a disconnect switch 58 to line L2 of power leads L1 and L2; it is further connect-able to L1 through parallel connections, one extending through the hold switch 56 and the other extending through the contacts 36 and 37 of switch 32.

In operation, when fluid reaches a predetermined pressure in switch 32 the contacts 36 and 37 engage andclose a circuit extending through the operating coil 52 and normally closed disconnect switch 58. The energization of coil 52 closes switch 56 and thereby establishes a holding circuit through coil 52 which will not be broken, even by the disengagement of the contacts of switch 32, until the disconnect switch 58 is opened. Primary switch '54 establishes a circuit through motor 41 of turning mechanism 40 so long as coil 52 remains energized. With this arrangement, coil 52 will remain energized even when slow rotation of the rotor 10 and disc 14 causes switch 32 to open. Disconnect switch 58 must be manually opened momentarily, therefore, and then reclosedto deenergize the turning motor 41 and condition the electrical system for subsequent operation; and this is usually done when starting up the turbine after shut-down, or after the rotor 10 has become cool.

While the invention has been shown in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What is claimed is:

1. A device for sensing a condition of rest of a shaft angularly movable about its axis, said device comprising: first means for providing at least two streams of energy vehicles, second means responsive to the receipt of energy from one or both streams, and a member movable incident to rotation of said shaft, said member including a series alternately comprising passageways and blocking elements for said streams, said series being movable with said member across the paths of said streams and arranged so that the positions of said passageways and said blocking elements with respect to said streams permits at least one stream of energy vehicles to flow to said second means when said shaft is at rest in any position.

2. A device for sensing a condition of rest of a rotor, said device comprising: first means for providing at least two streams of fluid, second means responsive to the receipt of fluid from one or both streams, and a member movable incident to rotation of said rotor, said member including a series alternately comprising passageways and blocking elements for said streams, said series being mov-- able with said member across the paths of said streams and arranged so that the positions of said passageways and said blocking elements with respect to said streams permits at least one stream of fluid to flow to saidsecond means when said rotor is stationary in any position.

3;'A device responsive to the condition of rest or movement of a rotor for actuating means responsive to the flow of energy, said device comprising: means providing at least twostreams of energyvehicles, and a member movable incident to rotationof said rotor; said member including aseries alternately comprising passageways and blocking elements for said streams, said series being movable with said member across the paths of said streams and arranged so that the positions of said passageways and said blocking elements with respect to said streams permits at least one stream of energy vehicles to flow when said rotor is stationary in any position, and means for directing said flow, said directing means being connectable to the energy responsive means.

4. A device responsive to the condition of rest or movement of a rotor for actuating means responsive to fluid pressure, said device comprising: means providing at least two streams of fluid, and a member movable incident to rotation of said rotor; said member including a series alternately comprising passageways and blocking elements for said streams, said series being movable with said member across the paths of said streams and arranged so that the positions of said passageways and said blocking elements with respect to said streams permits at least one stream of fluid to flow when said rotor is stationary in any position, and means for accumulating the fluid from said one stream, said accumulating means being connectable to the fluid responsive means.

5. A device for sensing the condition of rest or movement of a rotor comprising: first means providing at least two streams of energy vehicles, second means spaced from said first means and actuatable in response to the receipt of energy, said second means being provided with inlets for the respective streams, and a member movable between said first and second means incident to rotation of said rotor; said member including a series alternately comprising passageways and blocking elements for said streams, said series being movable with said member across the paths of said streams and arranged so that the position of said passageways and said blocking elements with respect to said streams permits at least one of said streams to flow through the associated one of said inlets to said second means when said rotor is stationary in any position, whereby said second means is actuated.

6. A device for sensing the condition of rest or movement of a rotor comprising: first means providing at least two streams of fluid, second means spaced from said first means and actuatable in response to the receipt of fluid, said second means being provided with inlets for the respective streams, and a rotatable member driven by said rotor between said first and second means; said member including an annular series alternately comprising passageways and blocking elements for said streams, said series being movable with said member across the paths of said streams and arranged so that the position of said passageways and said blocking elements with respect to said streams causes at least one stream to flow through the associated one of said inlets to said second means when said rotor is stationary in any position, whereby said second means is actuated.

7. A device, responsive to the condition of rest or movement of a rotor, for actuating control means of the fluid pressure responsive type, said device comprising: first means including fluid pressurizing means for providing at least two laterally spaced jets of fluid, second means providing inlets for the respective jets, each of said inlets being connectable to said control means, and a member movable incident to rotation of said shaft, said member including a series of spaced passageways for said jets movable with said member across the paths of said jets and arranged so that at least one or the other of said jets is always in registry with one of said passageways in any stationary position of said member, said jets .being deflected away from said inlets by said blocking elements during rotation of said rotor.

'8. A'device responsive to the condition of standstill or rotation of a rotor for actuating control means of the type responsive to fluid pressure, said device comprising: means for providing at least two fluid jets which are in spaced and generally parallel relation to one another, an inlet structure for each jet, connectable to said control means, anda movable member arranged to be driven by said rotor, said member including an alternating series of passageways and blocking elements movable transversely across the paths of said jets for respectively conducting and blocking said jets when in stationary registry therewith, the transverse extent of each'blocking element in the direction of movement of said series being substantially equal to the space between said jets, the transverse extent of each passageway in the direction of movement of said series being substantially equal to the aggregated transverse extent of one blocking element and both jets.

'9. A device responsive to the condition of standstill or rotation of a rotor for actuating fluid pressure responsive control means, said device comprising: first means for providing at least two fluid jets which are in spaced and generally parallel relation to one another, structure having an inlet aligned with each of said jets and connectable to said control means, a movable member arranged to be driven by said rotor, said member including a series movable transversely across the paths of said jets and comprised alternately of blocking elements and passageways for respectively blocking and conducting said jets when in stationary registry therewith, said blocking elements being of like configuration and each having a leading edge and a trailing edge one in front of the other, respectively, relative its direction of movement, the transverse extent of each passageway in the direction of movement of said series being substantially equal to the aggregated extent of one blocking element and both jets in the same transverse direction, said first means being arranged relative said series so that one jet will just clear one blocking element at the leading edge thereof when the other jet just clears another blocking element at the trailing edge thereof, whereby at least one or the other of said jets enters the inlet associated therewith and actuates said control means by fluid pressure when the rotor is at standstill in any position, said jets being deflected by said blocking elements during rotation of said rotor.

10. A device responsive to the condition of standstill or rotation of a rotor for actuating control means responsive to fluid pressure, said device comprising: means including a pair of conduits each having a nozzle at the outlet end thereof for providing at least two spaced fluid jets, tubular structure connectable between each conduit and the control means, and a movable member arranged to be driven by said rotor past the outlets of said nozzles, said member including an alternating series of passageways and blocking elements movable transversely across the paths of said jets for respectively unblocking and blocking said nozzles, the transverse extent of each passageway in the direction of movement of said series being substantially equal to the space between said jets, the transverse extent of each blocking element in the direction of movement of said series being substantially equal to the aggregated transverse extent of one passageway and both jets, whereby at least one of said nozzles is blocked when said movable member is at rest in any position.

11. In an elastic fluid turbine; a rotor, electrically operated means including an electric motor for turning said rotor at low speed after the turbine is shut down, switch means responsive to fluid pressure for energizing said motor, structure providing a pair of fluid chambers each connected to said switch means and having an inlet, means spaced from said structure for providing a pair of fluid jets and directing them toward the inlets, and a disc member rotatable with said rotor, said member including an annular series of equally spaced blocking elements and fluid passageways between said elements, said elements and .said passageways being movable transversely across the paths of said jets between said jet providing means and the inlets of said structure, the transverse extent of each'b'locking element being substantially equal to the space "between said jets, the transverse extent of each passageway being substantially equal to the aggregated extent in the same direction of one blocking element and both jets, at least one of said jets being directed through one of said inlets to its associated chamber in any stationary position of said member,-whereby said motor is energized, said jets being deflected by said blocking elements during rotation of said member.

No references cited. 

